a. used to = something is in the
past--similar to "did."
I used to eat a lot of candy, but now I don't because it's bad
for my teeth.
b. used to = accustomed to something; in the habit of.
I'm used to eating healthy food, whether it tastes good or not.
(a gerund often appears after "used to.")
Are you used to your computer, or is it difficult to operate?